Method of making printing devices.



J. S. DUNCAN.

METHOD OF MAKING PRINTING DEVIOES.

APPLICATION TILED MAR.23,1912.

Patented May 12, 1914.

UNITED STATES PATENT OFFICE.

JOSEPHS. DUNCAN, OF CHICAGO, ILLINOIS. ASSIGNOR T0 ADDRESSOGRAPHCOMPANY,

OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

METHOD OF MAKING PRINTING DEVICES.

Patented May 12, 1914.

Application filed March 23, 1912. Serial No. 685,813.

'1 '0 all whom it may concern:

Be it known that I, Josnrn S. DUNCAN, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Methods of MakingPrinting Devices,'of which the following is a specification. I

My present invention relates to the method of making printing devicesand has for its principal object the production of a printing devicehaving flat faced sharply defined printing characters Whereby even,uniform and sharply defined impressions may be made upon thepaper.

For the purpose of facilitating the explanation of my invention I havedisclosed on the accompanying drawings fragmentary views of aprintingdevice showing completed printing characters and the method ofproducing the same.

Referring to the drawings-Figure 1 is a fragmentary sectional view of aprinting device having printing characters stamped thereon and a meansfor finishing the said characters; Fig. 2 is a plan view of the printingdevice shown in Fig. 1; Fig. 3 is a fragmentary perspective view ofastamped up printing character before it is rolled; and Fig. i is aperspective view of a printing character after the same has beensubjected to the finishing or rolling operation.

Printing characters have been formed on metal blanks or sheets longprior to my present invention by stamping or striking up the charactersfrom the body of the blank and various machines equipped with punchesand dies for performing this operation have. been devised. The printingsurfaces of thecharacters formed in this way, however, are more or lesscurved, particularly near the edges, and consequently do not produceclear and sharply defined impressions. Further more, as the result ofunavoidable inaccuracies in the punches and dies and the machines foroperating the. same, some of the characters will be stamped up a greaterdistance ,than others so that the printing surfaces of variouscharacters lie in different planes, with the result that a heavierimpression is produced by some of the characters than by others.

My present invention aims to reduce the printing surfaces of all of theprinting characters on a plate or blank to a common plane and to provideeach of the characters with a flat printing surface having sharplydefined edges so that clear, uniform and sharply defined impressionswill be produced by every character on the device.

On the drawings reference character 5 designates, generally, a printingdevice which may be a metal blank sheet or frame of any preferredcontour and construction, the contour and construction of the device orblank being immaterial so far as my present invention is concerned. Inthe production of printing characters on this device or blank the metalis subjected to the action of punches and dies in the customary mannerto produce the printing characters desired in relief on one sidethereof. In the present instance the struck up characters produced bythe punching or stamping operation are designated by reference numeral6. The upper or printing surfaces of the struck up characters are moreor less curved as will be apparent from the drawings and the curvatureis particularly noticeable near the edges of the surfaces where themetal merges from the printing surfaces into the body of the characters.Owing to the unavoidable irregularities and imperfections in thepunches-and dies and in the operation of the machines the printingsurfaces of the various characters will not all be struck up the samedistance from the body of the blank and as a result uniformly clearimpressions can not be made by all of the characters. In order to reducethe printing surfaces of all of the characters'on the blank to a commonplane without removing any of the metal and in order to produce flatprinting surfaces having sharply defined edges I subject the blank withthe letters struck up therefrom to a rolling operation.

One practical method of producing the desired result is illustrated in aconventional manner in Fig. l where the plate is shown as positionedupon a bed 7 beneath a roller 8 mounted with its periphery apredetermined distance from the adjacent surface of the bed. The bed ispreferably mounted to move relatively to the roller but, obviously,the'roller might be moved relatively to the bed. In the present instancethe bed is movably mounted and as the bed travels in the direction ofthe arrow the printing characters stamped up on the metal blank will besubjected successively to the action of the roller and the upper'orprinting surfaces of the characters will be depressed into a commonplane and flattenedto produce sharply defined contours without weakeningthe structure or removing any of the metal. Obviously the bed might beheld stationary, if preferred, and the roller made to travel relativelyto the bed.

lhe characters which have or subjected to therolling operation areindicated on the drawings by reference numeral 9 and, from inspection ofFigs. 1 and 2, the difference in the characters before and after beingsnbjected'to the rolling operation will be readily apparent. Before therolling operation the characters have more or less curved printingsurfaces of irregular contour disposed in various planes while therolled or finished characters have flat sharply defined printingsurfaces all disposed in a common plane.

While I have shown on the drawings a series of capital Hs, it will beunderstood been worked iamaaea I that this letter'was selected merelyfor purposes'of illustration and that the entire alphabet in upper andlower case letters as Wellas numerals and other printing characters c'anbe accuratelyproduced bymy 3 improved method: a It will also beunderstood that my invention is not restricted to the illustrativedisclosure herein made but is capable of considerable variation withoutdeparting from the spirit of the invention or sacrificing any of thematerial advantages thereof.

' I claim:

The method of producing printing characters consisting in striking upfrom a metal sheet a plurality of raised printing characters and rollingthe tops of the characters without removing any of the material from theprinting characters to produce flat sharply defined printing surfacesall disposed in a common plane.

JOSEPH S. DUNCAN. Witnesses WM. 0. BELT, IRA J. WILSON.

